How to Verify ESD PCBAs Which Tests Are Needed

[NDesouza]

Hello
I am seeking help convincing my management team that we are experiencing early field failures and latent issues because we do not have a robust ESD program in place?
I cant find a single case study that specially calls out NON-ESD ESD compliant electrical torque screwdrivers as one of the root causes of ESD. I am just about to bang my head on the wall Does anyone know where I might find data on this?

 

[Tidge]

What are the sensitivity levels of the components in question? Do you think you have highly sensitive components?

IIRC ESD TR20.20 gives the overview of how to test for both human body model and charged device model... you could probably mimic the setup of one of those tests but instead of injecting a control charge bring the suspect tool into contact and capture the resulting waveform.

 

[ChrisM]

There is probably little data around surrounding damage caused by using non-ESD compliant screwdrivers because who in their right mind would use them in the presence of ESD sensitive items/materials? Can you find a good course or some training material surrounding electrostatic discharge and the damage it causes? When tracks inside ICs are sometimes only an atom or two wide, the risk of catastrophic damage is that much higher than when these tracks were 10 or more atoms wide... I was sent on a day's course around 20 years ago by my then-employer, run by a national expert on ESD and it was highly enlightening

 

[yodon]

The questions just come spewing out!

Why are you convinced that's the root cause (not saying you're wrong, just asking the question)? Have you done anything like a fault tree diagram to consider other means (and ruled everything else out?)? Backing up even further, why are (presumably) end users having to use a screwdriver (especially in a way that could enable damage to the PCB - instead of blaming screwdrivers, maybe the design is at fault?)? What data do you have / are you gathering?

If I was management, I'd want to have good data that conclusively backs up your assertion before taking action. (And I wouldn't likely buy some case study of non-ESD screwdriver use).

 

[ChrisM]

If I were Management, I'd want to be observing best industry practice as a bare minimum, and that would include the use of correct tools - ESD screwdrivers where ESD assemblies are being handled for a start; a proper ESD regime including dissipative bench mats with regular testing, correct operator clothing and chairs etc etc

 

[NDesouza]

The questions just come spewing out!

Why are you convinced that's the root cause (not saying you're wrong, just asking the question)? Have you done anything like a fault tree diagram to consider other means (and ruled everything else out?)? Backing up even further, why are (presumably) end users having to use a screwdriver (especially in a way that could enable damage to the PCB - instead of blaming screwdrivers, maybe the design is at fault?)? What data do you have / are you gathering?

If I was management, I'd want to have good data that conclusively backs up your assertion before taking action. (And I wouldn't likely buy some case study of non-ESD screwdriver use).

We are working to become AS9100 Certified and our current ESD program only addresses HBM and not CDM. The cheap electric torque screwdrivers are non compliant with all standards ESD related. We conclude that based on the non compliant current state of the ESD program, much improvement is needed. We want to use only ESD safe tools moving forward.

We have collected data from case studies on HBM and CDM, financial losses experienced by companies of similar processes, we have all sorts of proof the ESD is a THING.
We have not conducted ESD testing on our current cheap non ESD electric screwdrivers. We are preparing testing to prove our internal ESD gaps.
We also have 5 years of RMA data showing PCBA "related failure" these are likely latent failures caused by ESD events post shipping to customers. This has been happening before my time, as well as for the 9 months I have been working in the factory

 

[Ed Panek]

Try this:

Fastening: Avoiding ESD During Fastening

Electrostatic discharge is a constant danger during the assembly of electronic devices. By some estimates, assemblers lose 8 to 33 percent of product to damage caused by ESD, and fastening tools are often overlooked as a source of static buildup. This article explains how to prevent ESD from...

www.assemblymag.com

 

[Mike S.]

Have you considered using an electrostatic field meter to check the tools as they are being used?

 

[NDesouza]

Try this:

Fastening: Avoiding ESD During Fastening

Electrostatic discharge is a constant danger during the assembly of electronic devices. By some estimates, assemblers lose 8 to 33 percent of product to damage caused by ESD, and fastening tools are often overlooked as a source of static buildup. This article explains how to prevent ESD from...

www.assemblymag.com

Thank very much. We put together a small test using the tests you shared. We don't have some of the tools, but we used a basic Oscilloscope to show that the Non ESD safe electric Screwdrivers are not safe whether resting or in motion. We have one ESD safe electric screwdriver that we bought to test. The ESD safe tool clearly shows that it is safe whether resting or in motion.

I wish we had more tools and testing equipment